Mobile terminals are devices that may be freely used by being carried without restriction of place and typically include payment terminals used for credit cards, mobile communication terminals such as mobile phones, and personal digital assistants (PDAs) called personal portable terminals. Accordingly, the term “mobile terminal” may be interpreted to include all the above-described devices. In the following description, for convenience of explanation, the mobile terminal means the payment terminal.
The payment terminal stores or processes a large amount of important data, for example, personal information. Accordingly, using a tamper detection device for detecting tamper through hardware or software to hack the important data is necessary.
One typical tampering is hacking important data by disassembling a payment terminal. In other words, important data may be hacked from various circuit parts mounted on a printed circuit board by disassembling a case in which the printed circuit board is arranged.
Accordingly, a payment terminal of the related art includes a case disassembling recognition portion for recognizing disassembly of a case, and a hacking preventing portion connected to the case disassembling recognition portion and erasing important data when the case is disassembled.
The case disassembling recognition portion is configured in a switching method to recognize assembly and disassembly of the case. In other words, the case disassembling recognition portion includes a tamper detect pattern provided on the printed circuit board and having two conductive members arranged apart from each other, and a movable member movably provided between the printed circuit board and the case and electrically connecting the two conductive members through moving.
The case disassembling recognition portion recognizes assembly of the case as the movable member contacts the conductive member during assembly of the case, and disassembly of the case as the movable member is released from the contact with the conductive member during disassembly of the case.
However, the tempering becomes more complicated and a method of confusing the case disassembling recognition portion has developed.
One of the tampering is to inject a conductive liquid into the tamper detect pattern through a small hole formed in the case.
When the conductive liquid is injected into the tamper detect pattern, the two separated conductive members are electrically connected to each other through the conductive liquid. Thus, even when the movable member is released from the contact with the conductive member due to disassembly of the case, the case disassembling recognition portion may not recognize disassembly of the case.
Accordingly, there is a demand for development of a mobile terminal that may deal with tampering by confusing the case disassembling recognition portion like the method of injecting a conductive liquid into the tamper detect pattern.